The subject matter disclosed herein relates to a technique of a medical X-ray CT (Computed Tomography) apparatus or an industrial X-ray CT apparatus.
In an X-ray CT apparatus having a multi-row X-ray detector or an X-ray CT apparatus based on a two-dimensional X-ray area detector of a matrix structure typified by a flat panel, there has heretofore been a technique which photographs tomographic images at a plurality of X-ray tube voltages as shown in FIG. 7 and brings information about a difference between the dependencies of X-ray absorption coefficients of materials constituting a subject on the X-ray tube voltages into imaging, based on the tomographic images.